1. Field of the Invention
The present invention relates to a remote starting control system and, more particularly, relates to a remote starting control system to be mounted on a vehicle having an immobilizing function.
2. Description of the Relevant Art
Recently, the number of vehicles having an antitheft function called an immobilizer has been increasing. The implementation of the immobilizing function (for engines), as shown in FIG. 8, requires an ignition key 1 having a chip 3 which stores a specific code and has a transmitting feature built into its grip portion 2, a key cylinder 4, a transponder 5 installed on the key cylinder 4, an immobilizer 6 which stores a unique code of a vehicle and shows its antitheft function, and an engine controller 7 to control engine starting and the like.
When the ignition key 1 is inserted into the key cylinder 4 by a vehicle driver (or the ignition key 1 is turned to the ACC output position or the IG output position of an ignition switch), a key insertion detection signal becomes high. When receiving the signal, the immobilizer 6 sends a startup signal through a signal line L1 to the transponder 5.
When receiving the startup signal, the transponder 5 conducts radio communication with the chip 3 of the ignition key 1 inserted in the key cylinder 4 to acquire the specific code stored in the chip 3, and outputs the acquired specific code with a clock signal through a signal line L2 to the immobilizer 6.
The immobilizer 6 judges whether or not the specific code sent from the transponder 5 matches up with the unique code of the vehicle previously stored. When these codes are judged to be the same, the driver who inserted the ignition key 1 into the key cylinder 4 is considered as an authorized driver, so that a permission signal for permitting an engine start is given to the engine controller 7.
The engine controller 7 conducts engine control such as fuel and ignition timing, when receiving a starter signal output from the key cylinder 4 after receiving the permission signal. On the contrary, the engine controller 7 does not conduct the engine control when receiving the starter signal without receiving the permission signal.
As described above, unless the code stored in the chip 3 of the ignition key 1 is the unique code of the vehicle, it is impossible to start the engine. Therefore, the engine cannot be started with an improper ignition key or direct coupling of the ignition switch, so that vehicle theft can be prevented.
Meanwhile, remote starting control systems for starting a machine such as an engine by remote control have been in the actual use. As shown in FIG. 9, a remote starting control system 18, after receiving a signal instructing an engine start from a portable transmitter 19 a driver carries with him/her, provides false signals corresponding to an ACC signal, an IG signal and a starter signal output when a proper ignition key 11 is turned to the starter output position to a signal line L3 of an ignition switch so as to send these false signals to an engine controller 17.
Thus, without inserting the ignition key 11 into a key cylinder 14 and turning it, the engine can be started only by sending the signal instructing an engine start from the portable transmitter 19.
However, in cases where the remote starting control system 18 is additionally mounted on a vehicle having the above-described immobilizing function, the engine cannot be started even if the false signals (false signals of an ACC signal, an IG signal and a starter signal) are sent to the engine controller 7, since matching of the unique code of the vehicle stored in the immobilizer 6, or an insertion of the proper ignition key 1 into the key cylinder 4 is required.
In order to solve such problem, two inventions have been known: Japanese Patent Kokai 1998-176642 (Publicly-known Example 1), wherein a remote starting control system, previously storing a unique code of a vehicle, sends the unique code of the vehicle to an immobilizer after receiving an instruction of an engine start by remote control, and the immobilizer gives the permission signal to an engine controller; and Japanese Patent Kokai 2001-270424 (Publicly-known Example 2), wherein a small transmitter removed from a proper ignition key (which stores a unique code of a vehicle, corresponding to the above chip 3) and a transponder installed on a key cylinder are electrically connected through an antenna, and when an instruction of an engine start from a portable transmitter is received, the transponder is activated to send the unique code of the vehicle transmitted from the small transmitter through the antenna to an immobilizer.
However, in the invention described in the Publicly-known Example 1, mode conversion (selection of a preset mode) is conducted in storing the unique code of the vehicle in the remote starting control system, and an operating part for the mode conversion is additionally required, resulting in a higher cost. On the other hand, in the invention described in the Publicly-known Example 2, another proper ignition key must be prepared, resulting in an increase in cost, similarly to the above Publicly-known Example 1.